So I've joined the old camp as a shadow and milten's got the high magician's letter; but which reward is better for a warrior / strength type of character?

I've been reading around and apparently the best item to get is the + max mana potion, but am i really going to benefit from it?

I'd really like to go for the strength ring but i'm thinking that i might regret it later on..

Go for the Strength ring. +5 mana is only valuable to a magic user whereas a Strength boost is something you'll constantly benefit from for your chosen type of combat.

You'll have a few other chances to get permanent mana potions later on and with your non-magic focus missing out on one of these won't matter.